Full color display panel and color-separating substrate thereof

ABSTRACT

A full color display panel comprises an organic light-emitting area, a white-light producing layer, a color-separating layer and a transparent substrate. In this case, the organic light-emitting area comprises a plurality of pixels for emitting short wavelength light. The color-separating layer is doped with a fluorescent material and/or a phosphorescent material in a transparent protecting medium. The color-separating layer comprises a light-shielding frame and a plurality of color filters. The light-shielding frame is disposed around the peripheral of the color filters. The color-separating layer is disposed on the transparent substrate. The white-light producing layer is disposed above the color-separating layer. The organic light-emitting area is disposed above the white-light producing layer.

BACKGROUND OF THE INVENTION

[0001] 1. Field of Invention

[0002] The invention relates to a full color display panel and acolor-separating substrate and, in particular, to a full color displaypanel and a color-separating substrate comprising a white-lightproducing layer.

[0003] 2. Related Art

[0004] The colorizing technologies utilized in the present organicelectroluminescent displays mainly include the following three. Thefirst technology is “Three Primary Colors Light-emitting Method” thatuses respectively three primary colors (Red, Green, and Blue) for anindependent electroluminescent unit. The second technology is “ColorConversion Medium” that includes a blue light material and cooperateswith a red organic fluorescent material and a green organic fluorescentmaterial to generate various colors. The third technology is “ColorFilter Method” that includes white light electroluminescent layer andcolor filters. Hereinafter, the color conversion medium technology istaken for an example and is described below.

[0005] Idemitsu Kosan Co. is one of the leaders in developing the colorconversion medium technology. As shown in FIG. 1, a full color displaypanel 3 comprises an organic light-emitting area 31, a planarizationlayer 32, a color conversion layer 33, a glass substrate 34 and anencapsulating cap 35. The organic light-emitting area 31 is disposed onthe planarization layer 32, the planarization layer 32 is disposed onthe color conversion layer 33, the color conversion layer 33 is disposedon the glass substrate 34, and the encapsulating cap 35 is connected tothe glass substrate 34. In this case, the organic light-emitting area 31includes a first electrode 311, an organic functional layer 312 and thesecond electrode 313, which are disposed on the planarization layer 32in sequence. The organic functional layer 312 is made of a white lightmaterial, so that the organic light-emitting area 31 can emit whitelight. The color conversion layer 33 comprises a plurality of bluefilters 331, green filters 332, red filters 333, blue conversion films331′, green conversion films 332′, and red conversion films 333′. Theblue conversion films 331′, the green conversion films 332′ and the redconversion films 333′ are disposed on the blue filters 331, the greenfilters 332 and the red filters 333 respectively. The filters 331, 332,and 333 are respectively corresponding to the pixels of the organiclight-emitting area 31.

[0006] The white light emitted from the organic light-emitting area 31may pass through the blue conversion film 331′, green conversion film332′ and red conversion film 333′, and is respectively converted intoblue light, green light and red light. The blue light, green light andred light converted from the white light pass the blue filter 331, greenfilter 332 and the red filter 333 respectively, to increase the contrastof the blue light, the green light and the red light. Finally, a drivingcircuit is provided to produce the desired full color screen accordingto the generated three primary colors (red light (R), green light (G),and blue light (B)).

[0007] In the conventional full color display panel 3, however, since atleast three photolithography processes are necessary to form the blueconversion films 331′, the green conversion films 332′ and the redconversion films 333′ on the blue filters 331, the green filters 332 andthe red filters 333, the manufacturing processes of the full colordisplay panel 3 are more complex and the cost thereof is increased.Furthermore, since the full color display panel 3 includes theplanarization layer 32 to make the whole panel more planar, thethickness of the whole panel 3 is also increased, which did not followthe trend toward lightweight and compact devices.

[0008] It is therefore a target to provide a full color display paneland a color-separating substrate thereof to solve the above-mentionedproblems.

SUMMARY OF THE INVENTION

[0009] In view of the foregoing, the invention is to provide a fullcolor display panel and a color-separating substrate thereof, which arewithout the conventional planarization layer and do not respectivelyutilize the color conversion films of three primary colors (R, G, B).

[0010] To achieve the above, the full color display panel of theinvention comprises an organic light-emitting area, a white-lightproducing layer, a color-separating layer and a transparent substrate.In this invention, the organic light-emitting area includes a pluralityof pixels for emitting short wavelength light. The white-light producinglayer includes a protecting medium, which is transparent and is dopedwith a fluorescent material and/or a phosphorescent material. Thecolor-separating layer includes a light-shielding frame and a pluralityof color filters, wherein the light-shielding frame is disposed aroundthe peripheral of the color filters. The color-separating layer isdisposed on the transparent substrate. The white-light producing layeris disposed above the color-separating layer. The organic light-emittingarea is disposed above the white-light producing layer.

[0011] To achieve the above, a color-separating substrate of theinvention comprises a white-light producing layer, a color-separatinglayer and a transparent substrate. In this invention, the white-lightproducing layer includes a protecting medium, which is transparent andis doped with a fluorescent material and/or a phosphorescent material.The color-separating layer includes a light-shielding frame and aplurality of color filters, wherein the light-shielding frame isdisposed around the peripheral of the color filters. Thecolor-separating layer is disposed on the transparent substrate. Thewhite-light producing layer is disposed above the color-separatinglayer.

[0012] As mentioned above, the full color display panel andcolor-separating substrate thereof of the invention has a white-lightproducing layer, which is used to translate the short wavelengthultraviolet or blue light into white light and to enhance theluminescent efficiency of the organic light-emitting area. Therefore,the white light with uniform and broadband radiation spectrum can beobtained, and satisfy the application of full color displays. Comparingwith the conventional art, since the planarization layer is unnecessaryin the invention, the structure of the full color display panel of theinvention is simplified. At the meanwhile, the thickness of the panel ofthe invention is reduced. In addition, since it is unnecessary toperform the photolithography processes to form the color conversionfilms of three primary colors (R, G, B), the manufacturing processes ofthe full color display panel are simplified and the cost thereof isdecreased, and the manufacturing yield is increased. Furthermore, sinceit is not to be restricted by the areas of the color conversion films,the viewing angle of the panel can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will become more fully understood from the detaileddescription given hereinbelow illustration only, and thus is notlimitative of the present invention, and wherein:

[0014]FIG. 1 is a schematic view showing the conventional full colordisplay panel;

[0015]FIG. 2 is a schematic view showing a full color display panelaccording to a first embodiment of the invention;

[0016]FIG. 3 is a schematic view showing another full color displaypanel according to the first embodiment of the invention;

[0017]FIG. 4 is a schematic view showing yet another full color displaypanel according to the first embodiment of the invention; and

[0018]FIGS. 5A to 5C are a set of schematic views showing acolor-separating substrate according to a second embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be apparent from the followingdetailed description, which proceeds with reference to the accompanyingdrawings, wherein the same references relate to the same elements.

[0020] With reference to FIG. 2, a full color display panel 1 accordingto the first embodiment of the invention comprises an organiclight-emitting area 11, a white-light producing layer 12, acolor-separating layer 13 and a transparent substrate 14. In thisembodiment, the organic light-emitting area 11 comprises a plurality ofpixels for emitting short wavelength light. The white-light producinglayer 12 comprises a protecting medium, which is transparent and isdoped with a fluorescent material and/or a phosphorescent material. Thecolor-separating layer 13 comprises a light-shielding frame 131 and aplurality of color filters 132. The light-shielding frame 131 isdisposed around the peripheral of the color filters 132. Thecolor-separating layer 13 is disposed on the transparent substrate 14.The white-light producing layer 12 is disposed above thecolor-separating layer 13. The organic light-emitting area 11 isdisposed above the white-light producing layer 12.

[0021] As shown in FIG. 2, the organic light-emitting area 11 comprisesa plurality of pixels for emitting short wavelength light. The pixelcomprises a first electrode 111, an organic functional layer 112, and asecond electrode 113. The first electrode 111 is disposed above thewhite-light producing layer 12. The second electrode 113 is disposedabove the first electrode 111, and the organic functional layer 112 issandwiched between the first electrode 111 and the second electrode 113.

[0022] In such a case, the first electrode 111 is formed above thewhite-light producing layer 12 by a sputtering method or an ion platingmethod. The first electrode 111 is usually used as an anode and made ofa transparent conductive metal oxide, such as indium-tin oxide (ITO),aluminum-zinc oxide (AZO), or indium-zinc oxide (IZO).

[0023] The organic functional layer 112 in the current embodiment isdisposed on the first electrode 111. The organic functional layer 112usually may contain a hole injection layer, a hole transporting layer,an electroluminescent layer, an electron transporting layer, and anelectron injection layer (not shown). The hole injection layer comprisescopper phthalocyanine (CuPc), the hole transporting layer comprises4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), the electroninjection layer comprises lithium fluoride (LiF), and the electrontransporting layer comprises tris(8-quinolinato-N1,08)-aluminum (Alq).Each layer of the organic functional layer 112 may be formed upon thefirst electrode by utilizing evaporation, spin coating, ink jetprinting, or printing. Herein, the light emitted from the organicfunctional layer 112 is short wavelength light such as ultraviolet lightor blue light.

[0024] The second electrode 113 is disposed on the organic functionallayer 112. Herein, the second electrode 113 is formed on the organicfunctional layer 112 by way of evaporation or sputtering. The materialof the second electrode 113 can be aluminum, calcium, andmagnesium-silver alloys. Of course, the material of the second electrode113 can also be aluminum/lithium fluoride, or silver.

[0025] Please refer to FIG. 2 again. The white-light producing layer 12is disposed above the color-separating layer 13, and comprises aprotecting medium, which is transparent and is doped with a fluorescentmaterial and/or a phosphorescent material. The fluorescent materialand/or the phosphorescent material of the white-light producing layer 12can mix, scatter and excite the emitted from the organic light-emittingarea 11, so as to translate the short wavelength light (ultravioletlight or blue light) emitted from the organic light-emitting area 11into white light. Thus, the invention can enhance the luminescentefficiency of the organic light-emitting area 11. Therefore, the whitelight with uniform and broadband radiation spectrum can be obtained.Furthermore, the demands of the color display panel can be satisfied.Moreover, the white-light producing layer 12 is a planar structure witha single layer, which can also provide a planarization effect.

[0026] In this embodiment, the material of the protecting medium can beselected from but not limited to the group consisting of Polymethylmethacrylate (PMMA), tetrafluoroethylene resin, silicon resin, andsilicon dioxide.

[0027] The protecting medium can be used to protect the first electrode111 and the second electrode 113. Since the protecting medium isadhesive, it can be used to attach with a cover plate 15. In otherwords, it is unnecessary to apply a sealing glue, and the encapsulationprocess can still be performed. In addition, the protecting medium iswaterproof. The protecting medium can combine with the cover plate 15 orthe passivation layer of the organic light-emitting area 11 (not shown)to form an encapsulation. Thus, the organic light-emitting area 11 canbe prevented from water or oxygen.

[0028] In the current embodiment, the fluorescent material can beproduced by mixing red fluorescent powder, green fluorescent powder,and/or blue fluorescent powder. The phosphorescent material can beproduced by mixing red phosphorescent powder, green phosphorescentpowder, and/or blue phosphorescent powder.

[0029] As mentioned above, the fluorescent material may include morethan one organic dyes or more than one inorganic dyes. Herein, the redfluorescent powder may be an azo dye (organic dye) or Y₂O₂S:Eu³⁺, Bi³⁺(inorganic dye). The green fluorescent powder may be a CuPc dye (organicdye) or SrGa₂O₄:Eu²⁺ (inorganic dye). The blue fluorescent powder may bea cyanine dye (organic dye) or SrGa₂S₄:Eu²⁺ (inorganic dye). In thisembodiment, the fluorescent material may be nano sized powder.

[0030] In addition, the phosphorescent material may include more thanone organic dye or more than one inorganic dye. In the embodiment, thered phosphorescent powder may be2,3,7,8,12,13,17,18-octaethyl-12H,23H-porphine platinum(II) [PtOEP] orTris-(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanediono)-1,10-phenanthrolineeuropium(III) [Eu(TTA)3phen]. The green phosphorescent powder may beBis(2-phenyl-pyridinato-N,C2)iridium(acetylacetone) [ppy2Ir(acac)] orIridium(III) bis(tolypyridine) salicyclidene [tpyIrsd]. The bluephosphorescent powder may beIridium-bis(4,6-di-fluorophenyl-pyridinato-N,C2)-picolinate [Firpic] orBis[(4,6-difluorophenyl-pyridinato-N,C2)iridium(acetylacetone)[Fir(acac)]. In this embodiment, the phosphorescent material may be nanosized powder.

[0031] Referring to FIG. 2, the color-separating layer 13 comprises aplurality of color filters 132 surrounded with a light-shielding frame131. Herein, the light-shielding frame 131 is a black frame, which canavoid the mixing of lights of various colors. Of course, thelight-shielding frame 131 can be made of reflective metal forcontrolling the direction of the light and increasing the utilizationand uniformity of light. In addition, the light-shielding frame 131 canbe protruded out of the white-light producing layer 12 (as shown in FIG.3).

[0032] The color filters 132 comprise at least one red filter 1321, atleast one blue filter 1322, and at least one green filter 1323. In thecurrent embodiment, the high purity white light produced by thewhite-light producing layer 12 respectively passes the red filters 1321,the blue filters 1322 and the green filters 1323, so as to produce redlight, blue light and green light.

[0033] Please refer to FIG. 2 again. The transparent substrate 14 of theembodiment can be a flexible or rigid substrate. The transparentsubstrate 14 can also be a plastic or glass substrate. In particular,the flexible substrate or plastic substrate can be made of polycarbonate(PC), polyester (PET), cyclic olefin copolymer (COC), ormetallocene-based cyclic olefin copolymer (mCOC).

[0034] As shown in FIG. 2, the full color display panel 1 of theembodiment may further comprise an insulating layer 16, which isdisposed between the white-light producing layer 12 and the organiclight-emitting area 11. Thus, the insulating layer 16 can prevent thesubstantially contact of the white-light producing layer 12 and theorganic light-emitting area 11, which leads to short circuit. Herein,the insulating layer 16 is transparent and can be made of an organiccompound or inorganic compound.

[0035] In addition, the full color display panel 1 of the embodiment mayfurther comprise a pixel defining layer 17. The pixel defining layer 17is disposed on the first electrode 111 and/or the transparent substrate14 to define pixels within the organic light-emitting area 11. The pixeldefining layer 17 may be black to shield or reflect light. This couldavoid mixing of the light emitted from the pixels, control the directionof the light, and increase the utilization and uniformity of light. Inthe embodiment, the light-shielding frame 131 protruded from thewhite-light producing layer 12 may connect to the pixel defining layer17 (as shown in FIG. 3).

[0036] The full color display panel 1 of the embodiment may furthercomprise a separating layer 18, which is disposed on the pixel defininglayer 17. The separating layer 18 can separate each pixel of the organiclight-emitting area 11. In this case, the separating layer 18 is made ofan insulating material and has a top width larger than a bottom widththereof.

[0037] In general, the separating layer 18 is provided in a passivematrix full color display panel, such as a PMOLED, to separate thecathodes of the pixels for simplifying manufacturing processes. Inaddition, an active matrix full color display panel, such as an AMOLED,has thin-film transistors (TFT) for controlling the pixels, so theseparating layer 18 is unnecessary (as shown in FIG. 4).

[0038] Moreover, the full color display panel 1 of the embodiment mayfurther comprise a driving circuit (not shown). The driving circuit canbe an active driving circuit or a passive driving circuit. The drivingcircuit is connected to the organic light-emitting area 11 and a powersource (not shown).

[0039] With reference to FIG. 5A, a color-separating substrate 2according to a second embodiment of the invention comprises awhite-light producing layer 21, a color-separating layer 22, and atransparent substrate 23. Herein, the white-light producing layer 21comprises a transparent protecting medium doped with a fluorescentmaterial and/or a phosphorescent material. The fluorescent materialand/or the phosphorescent material can be excited by the shortwavelength light and then emit white light. The color-separating layer22 comprises a plurality of color filters 222 surrounded with alight-shielding frame 221. The color-separating layer 22 is disposed onthe transparent substrate 23, and the white-light producing layer 21 isdisposed above the color-separating layer 22.

[0040] In addition, as shown in FIG. 5B and FIG. 5C, the light-shieldingframe 221 may protrude out of the white-light producing layer 21.

[0041] Since the features and functions of the elements in the secondembodiment are the same as those in the first embodiment, they are notrepeatedly described hereinafter.

[0042] In brief, the full color display panel and color-separatingsubstrate thereof of the invention has a white-light producing layer,which is used to translate the short wavelength ultraviolet or bluelight into white light and to enhance the luminescent efficiency of theorganic light-emitting area. Therefore, the white light with uniform andbroadband radiation spectrum can be obtained, and satisfy theapplication of full color displays. Comparing with the conventional art,since the planarization layer is unnecessary in the invention, thestructure of the full color display panel of the invention issimplified. At the meanwhile, the thickness of the panel of theinvention is reduced. In addition, since it is unnecessary to performthe photolithography processes to form the color conversion films ofthree primary colors (R, G, B), the manufacturing processes of the fullcolor display panel are simplified and the cost thereof is decreased,and the manufacturing yield is increased. Furthermore, since it is notto be restricted by the areas of the color conversion films, the viewingangle of the panel can be increased.

[0043] Although the invention has been described with reference tospecific embodiments, this description is not meant to be construed in alimiting sense. Various modifications of the disclosed embodiments, aswell as alternative embodiments, will be apparent to persons skilled inthe art. It is, therefore, contemplated that the appended claims willcover all modifications that fall within the true scope of theinvention.

What is claimed is:
 1. A full color display panel, comprising: anorganic light-emitting area, which comprises a plurality of pixels foremitting short wavelength light; a white-light producing layer, whichcomprises a transparent protecting medium doped with a fluorescentmaterial and/or a phosphorescent material; a color-separating layer,which comprises a plurality of color filters surrounded with alight-shielding frame; and a transparent substrate, wherein thecolor-separating layer is disposed on the transparent substrate, thewhite-light producing layer is disposed above the color-separatinglayer, and the organic light-emitting area is disposed above thewhite-light producing layer.
 2. The full color display panel of claim 1,further comprising: an insulating layer, which is disposed between thewhite-light producing layer and the organic light-emitting area.
 3. Thefull color display panel of claim 1, wherein the pixel comprises a firstelectrode, an organic functional layer, and a second electrode, thefirst electrode is disposed above the white-light producing layer, thesecond electrode is disposed above the first electrode, and the organicfunctional layer is disposed between the first electrode and the secondelectrode.
 4. The full color display panel of claim 3, furthercomprising: a pixel defining layer, which is disposed on the firstelectrode and/or the transparent substrate to define pixels within theorganic light-emitting area.
 5. The full color display panel of claim 4,further comprising: a separating layer, which is disposed on the pixeldefining layer.
 6. The full color display panel of claim 1, wherein thecolor filters are provided corresponding to the pixels of the organiclight-emitting area.
 7. The full color display panel of claim 1, whereinthe material of the protecting medium is at least one selected from thegroup consisting of polymethyl methacrylate, tetrafluoroethylene resin,silicon resin, and silicon dioxide.
 8. The full color display panel ofclaim 1, wherein the protecting medium is adhesive or waterproof forattaching with a cover plate.
 9. The full color display panel of claim1, wherein the fluorescent material is mixed with red fluorescentpowder, green fluorescent powder, and/or blue fluorescent powder, andthe phosphorescent material is mixed with red phosphorescent powder,green phosphorescent powder, and/or blue phosphorescent powder.
 10. Thefull color display panel of claim 1, wherein the light-shielding frameis protruded out of the white-light producing layer.
 11. The full colordisplay panel of claim 1, wherein the color filters comprise at leastone red filter, at least one blue filter, and at least one green filter.12. The full color display panel of claim 1, wherein the shortwavelength light is ultraviolet light or blue light.
 13. Acolor-separating substrate, comprising: a white-light producing layer,which comprises a transparent protecting medium doped with a fluorescentmaterial and/or a phosphorescent material, wherein the fluorescentmaterial and/or the phosphorescent material is excited by shortwavelength light to emit white light; a color-separating layer, whichcomprises a plurality of color filters surrounded with a light-shieldingframe; and a transparent substrate, wherein the color-separating layeris disposed on the transparent substrate, and the white-light producinglayer is disposed above the color-separating layer.
 14. Thecolor-separating substrate of claim 13, further comprising: aninsulating layer, which is disposed above the white-light producinglayer.
 15. The color-separating substrate of claim 13, wherein thematerial of the protecting medium is at least one selected from thegroup consisting of polymethyl methacrylate, tetrafluoroethylene resin,silicon resin, and silicon dioxide.
 16. The color-separating substrateof claim 13, wherein the fluorescent material is mixed with redfluorescent powder, green fluorescent powder, and/or blue fluorescentpowder, and the phosphorescent material is mixed with red phosphorescentpowder, green phosphorescent powder, and/or blue phosphorescent powder.17. The color-separating substrate of claim 13, wherein thelight-shielding frame is protruded out of the white-light producinglayer.
 18. The color-separating substrate of claim 13, wherein the colorfilters comprise at least one red filter, at least one blue filter, andat least one green filter.
 19. The color-separating substrate of claim13, wherein the transparent substrate is at least one selected from thegroup consisting of flexible substrate, rigid substrate, plasticsubstrate and glass substrate.
 20. The color-separating substrate ofclaim 13, wherein the short wavelength light is ultraviolet light orblue light.